some writers have no credibility because their agenda is see through.
take columnist richard baehr of american thinker. he wrote a foolish column about how obama is the wrong choice for democrats but if you google his name and "barack obama," you come up with a series of scathing stories by the man who may be american but is no thinker. he just hates obama.
his hate goes back a ways. in this 2006 story, he says the media made obama who he is. there are tinges of racism there (from the story: But as John McWhorter asks, would any of these attributes been enough to have gotten Obama where he is today, were he not black?) uh, yes, yes he would. i've found this topic of racism fascinating because on one hand you have the outright racists-- those appalachians -- then you have the ones who are college educated and are bright in some regards but offer a more subtle racism, so subtle that they don't even see it in themselves.
here's another that says jewish people won't vote for obama.